17 research outputs found

    Speed detection to suppress motion artifacts (MA) in laser speckle contrast imaging

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    Introduction: Laser speckle contrast imaging (LSCI) is an optical technique for noninvasive assessment of microcirculatory blood flow. LSCI has a broad application in medicine including dermatology. Since laser speckles are the basis for this imaging modality, any external motions during a measurement from both patient and operator affect the blood flow images. This challenge is called motion artefacts (MA).Objective: Here, we propose a complete procedure for analysis of speckles, that is, pre-segmentation, segmentation, motion detection, spatial alignment, perfusion map calculation and MA suppression.Methods: The handheld perfusion imager (HAPI) operated in both handheld and mounted schemes, has been used for measurements on 14 psoriasis subjects. We make use of the black marker dots (made by the clinical investigator to determine visual psoriasis lesion boundaries) for calculation of two-dimensional displacements of HAPI during each measurement (i.e. on-surface displacements). Results: We have integrated the on-surface displacements to translate each speckle image back to the initial position at the start of the measurement (i.e. spatial alignment). Moreover, in handheld measurements, MA corrected blood flow maps (also called perfusion maps) are formed by extrapolation of a linear fit from local perfusion versus detected speed to the zero speed, that is, a value ideally always lower than the local mean perfusion.Conclusion: Using a single camera for both speckle imaging and motion detection, we have shown that our MA suppression technique makes handheld perfusion maps fairly similar to the associated mounted perfusion maps not only visually but also in terms of image histograms and mean values.<br/

    Perfusion measured by laser speckle contrast imaging as a predictor for expansion of psoriasis lesions

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    BACKGROUND: Skin microvasculature changes are crucial in psoriasis development and correlate with perfusion. The noninvasive Handheld Perfusion Imager (HAPI) examines microvascular skin perfusion in large body areas using laser speckle contrast imaging (LSCI). OBJECTIVES: To (i) assess whether increased perilesional perfusion and perfusion inhomogeneity are predictors for expansion of psoriasis lesions and (ii) assess feasibility of the HAPI system in a mounted modality. METHODS: In this interventional pilot study in adults with unstable plaque psoriasis, HAPI measurements and color photographs were performed for lesions present on one body region at week 0, 2, 4, 6 and 8. The presence of increased perilesional perfusion and perfusion inhomogeneity was determined. Clinical outcome was categorized as increased, stable or decreased lesion surface between visits. Patient feedback was collected on a 10‐point scale. RESULTS: In total, 110 lesions with a median follow‐up of 6 (IQR 6.0) weeks were assessed in 6 patients with unstable plaque psoriasis. Perfusion data was matched to 281 clinical outcomes after two weeks. A mixed multinomial logistic regression model revealed a predictive value of perilesional increased perfusion (OR 9.90; p < 0.001) and perfusion inhomogeneity (OR 2.39; p = 0.027) on lesion expansion after two weeks compared to lesion stability. HAPI measurements were considered fast, patient‐friendly and important by patients. CONCLUSION: Visualization of increased perilesional perfusion and perfusion inhomogeneity by noninvasive whole field LSCI holds potential for prediction of psoriatic lesion expansion. Furthermore, the HAPI is a feasible and patient‐friendly tool

    Handheld versus mounted laser speckle contrast perfusion imaging demonstrated in psoriasis lesions

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    Enabling handheld perfusion imaging would drastically improve the feasibility of perfusion imaging in clinical practice. Therefore, we examine the performance of handheld laser speckle contrast imaging (LSCI) measurements compared to mounted measurements, demonstrated in psoriatic skin. A pipeline is introduced to process, analyze and compare data of 11 measurement pairs (mounted-handheld LSCI modes) operated on 5 patients and various skin locations. The on-surface speeds (i.e. speed of light beam movements on the surface) are quantified employing mean separation (MS) segmentation and enhanced correlation coefficient maximization (ECC). The average on-surface speeds are found to be 8.5 times greater in handheld mode compared to mounted mode. Frame alignment sharpens temporally averaged perfusion maps, especially in the handheld case. The results show that after proper post-processing, the handheld measurements are in agreement with the corresponding mounted measurements on a visual basis. The absolute movement-induced difference between mounted-handheld pairs after the background correction is 16.4±9.3% (mean ± std, n= 11), with an absolute median difference of 23.8 %. Realization of handheld LSCI facilitates measurements on a wide range of skin areas bringing more convenience for both patients and medical staff

    Reliability of handheld laser speckle contrast perfusion imaging demonstrated in psoriasis lesions

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    We assessed the reliability of handheld laser speckle contrast perfusion imaging by evaluating mounted/handheld measurement pairs operated on psoriasis lesions in three steps. First, we made a denoised perfusion map per measurement based on spatial alignment of raw speckle frames and temporal averaging of perfusion frames. Second, we used the measured on-surface speed information to compensate the movement-induced perfusion by extrapolation of the local perfusion values to the value corresponds to zero on-surface speed. Third, we compared mounted/handheld measurement pairs based on perfusion inhomogeneity and increased perilesional perfusion criteria independent of the movement artefact compensation mentioned in the second step. We conclude that after proper post-processing, handheld LSCI measurements can be as reliable as mounted measurements in terms of geometrical distorting, but with challenges to be overcome for correcting perfusion values

    Beliefs About Medicines in Patients with Psoriasis Treated with Methotrexate or Biologics: A Cross-sectional Survey Study

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    Methotrexate (MTX) and biologics are frequently used treatments for psoriasis. Exploring patients’ beliefs about their treatment may help to elucidate patients’ attitudes towards these therapies. A cross-sectional survey was conducted using the Beliefs about Medicines Questionnaire-Specific (BMQ-Specific) in patients treated with methotrexate or biologics. BMQ-Specific scores (Necessity and Concerns scales) were calculated and patients were classified as “accepting”, “indifferent”, “ambivalent” or “sceptical” towards their treat­ment. Biologics users scored higher on the Necessity scale than did methotrexate users. Both groups had lower Concerns scores than Necessity scores. A high Necessity scale was associated with a low Psoriasis Area and Severity Index score in both groups and long treatment duration in the methotrexate group. Although this study cannot make a direct comparison, it was observed that most patients on biologics could be classified as “accepting” (59%), and most patients on MTX could be classified as “indifferent” (47%). In conclusion, the BMQ-Specific is useful to identify patients with a sceptical, ambivalent or indifferent profile. These profiles may negatively influence patient’s attitude towards their medication

    Efficacy of topical tacrolimus 0.1% in active plaque morphea: randomized, double-blind, emollient-controlled pilot study.

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    Item does not contain fulltextBACKGROUND: Tacrolimus, a calcineurin inhibitor, is an immunomodulating and anti-inflammatory drug that inhibits T-cell activation and production of cytokines. The elevated level of cytokines in morphea causes fibroblast proliferation and subsequent overproduction of collagen. Theoretically, tacrolimus could inhibit the pathophysiologic process of morphea. OBJECTIVE: To assess whether tacrolimus 0.1% ointment is an effective treatment for active plaque morphea in a double-blind, placebo (petroleum emollient)-controlled pilot study. METHODS: Ten patients with active plaque morphea were included. All patients were treated with tacrolimus 0.1% ointment and with an emollient (petrolatum) on two selected morphea plaques, applied twice daily for 12 weeks. Initial and final assessment included surface area measurements, photography, durometer scores, and clinical feature scores. Adverse reactions were recorded. RESULTS: The scleroderma plaques treated with topical tacrolimus 0.1% improved, resulting in a significant reduction in durometer and clinical feature scores. Overall, a significant difference could be found between topical tacrolimus and petrolatum with regard to durometer score (p < 0.005) and the clinical feature score (p = 0.019). CONCLUSION: In this first double-blind, placebo-controlled pilot study comparing tacrolimus 0.1% ointment with petrolatum in active plaque morphea, tacrolimus 0.1% ointment was shown to be an effective treatment for this condition

    Is Telemedicine Suitable for Patients with Chronic Inflammatory Skin Conditions? A Systematic Review

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    Telemedicine, the provision of remote healthcare, has gained prominence, accelerated by the COVID-19 pandemic. It has the potential to replace routine in-person follow-up visits for patients with chronic inflammatory skin conditions. However, it remains unclear whether telemedicine can effectively substitute in-person consultations for this patient group. This systematic review assessed the effectiveness and safety of telemedicine compared with traditional in-person care for chronic inflammatory skin diseases. A comprehensive search in various databases identified 11 articles, including 5 randomized controlled trials (RCTs) and 1 clinical controlled trial (CCT). These studies evaluated telemedicine’s impact on patients with psoriasis and atopic dermatitis, with varying methods like video consultations and digital platforms. The findings tentatively suggest that telemedicine does not seem to be inferior compared with in-person care, particularly in terms of condition severity and quality of life for patients with chronic inflammatory skin diseases. However, these results should be interpreted with caution due to the inherent uncertainties in the evidence. There are indications that telemedicine can offer benefits such as cost-effectiveness, time savings, and reduced travel distances, but it is important to recognize these findings as preliminary, necessitating further validation through more extensive research
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